How do you reuse a visual mode selection?

Question

Often when editing code, I'll select a block in visual mode and do a search and replace over the block. After I make the changes, however, it leaves visual mode. How do a new find and replace over the same selection?

Answer 1

You may re-select the last selected visual area with "gv".

Answer 2

Suppose I wanted to replace Goodbye with Hello and the code below was selected:

public static void main(String[] args){
    System.out.println("Goodbye World");
}

I would type in :s/Goodbye/Hello/ and vim will replace all instances of Goodbye with Hello

It's simply a combination of vim's regular expressions and visual mode selections. When you select, it should autofill '<,'>